(a) Field of the Invention
The present invention relates to a liquid crystal display having a wide viewing angle.
(b) Description of the Related Art
Generally, a conventional liquid crystal display (LCD) includes two substrates having electrodes and liquid crystal injected therebetween. The voltage difference between the electrodes yields an electric field, and the molecules of the liquid crystal are re-arranged by the electric field. The polarization of incident light is varies due to the re-arrangement of the liquid crystal molecules.
Hereinafter, the conventional LCD is explained in detail with reference to the accompanying drawings.
FIGS. 1A and 1B are sectional views of a conventional twisted-nematic liquid crystal display (TN-LCD). The TN-LCD in FIG. 1A includes transparent glass substrates 1 and 2 facing each other, a liquid crystal layer 7 inserted between the substrates 1 and 2, and electrodes 3 and 4 formed respectively on the inner surfaces of the substrates 1 and 2, and polarizing plates 5 and 6 for polarizing the light are attached to the outer surfaces of the glass substrates 1 and 2 respectively.
The electrode 3 of the lower substrate 1 is a pixel electrode, the electrode 4 of the upper substrate 2 is a common electrode, and dielectric anisotropy Δ∈ of the liquid crystal layer 7 is positive.
In the absence of an electric field, the long axes of the liquid crystal molecules 8 of the liquid crystal layer 7 are parallel to the substrates 1 and 2, and the liquid crystal molecules 8 are twisted spirally from one substrate to the other substrate.
When a power V is connected to the electrodes 3 and 4, and a sufficient electric field is applied to the liquid crystal layer 7 in the direction of the arrow as illustrated in FIG. 1B, the long axes of the liquid crystal molecules 8 are parallel to the direction of the electric field. This type of TN-LCD unfortunately results in having a narrow viewing angle.